An assay device includes a filter stack in an enclosure having a base portion and a lid. The filter stack has a hydrophilic membrane having a binder for an analyte thereon, a hydrophobic membrane under the hydrophilic membrane and a pad of absorbent material under the hydrophobic membrane. The lid includes...http://www.google.com/patents/US5185127?utm_source=gb-gplus-sharePatent US5185127 - Test device including flow control means
